Injectable, electrosprayed RGD-coupled alginate hydrogel microcapsules enable enhanced viability and sustained release of mesenchymal stem cells.

Casting Doubt on the Safety of “Off-the-shelf” Mesenchymal Stem Cells for Cell Therapy

Human stromal (mesenchymal) stem cells (hMSC) represent a group of non-hematopoietic stem cells present in the bone marrow stroma and the stroma of other organs including subcutaneous adipose tissue, placenta, and muscles. They exhibit the characteristics of somatic stem cells of self-renewal and multi-lineage differentiation into mesoderm-type of cells, e.g., to osteoblasts, adipocytes, chondrocytes and possibly other cell types including hepatocytes and astrocytes. Due to their ease of culture and multipotentiality, hMSC are increasingly employed as a source for cells suitable for a number of clinical applications, e.g., non-healing bone fractures and defects and also non-skeletal degenerative diseases like heart failure. Currently, the numbers of clinical trials that employ MSC are increasing. However, several biological and biotechnological challenges need to be overcome to benefit from the full potential of hMSC. In this current review, we present some of the most important and recent advances in understanding of the biology of hMSC and their current and potential use in therapy.

Extracorporeal membrane oxygenation (ECMO) is a well-known therapy for refractory cardiac and respiratory failure. Stem cell therapy has been investigated as an adjunctive treatment for use during ECMO, but little is known about the viability of stem cells during ECMO support. We evaluated the viability and activity of mesenchymal stem cells (MSCs) in ex vivo circulation (EVC) conditions. The experimental groups were divided into two subgroups: EVC with oxygenator (OXY group) and EVC without oxygenator (Non-OXY group). Mesenchymal stem cells (1.0 × 10) were injected into the EVC system. Cell counting, a lactate dehydrogenase (LDH) cytotoxicity assay, and the mitochondrial functions of viable MSCs were analyzed. The post-EVC oxygen consumption rate (OCR) was significantly lower than the pre-EVC OCR, regardless of whether the oxygenator was used. The LDH levels were significantly higher in the OXY group than in the Non-OXY group. The cellular loss was mainly due to lysis of the cells whereas the loss of cellular activity was attributed to the nonphysiologic condition itself, as well as the oxygenator. We concluded that direct infusion of MSCs during ECMO support did not serve as adjunctive therapy. Further studies are needed to improve the viability in an ECMO setting.

Recent studies indicate that cardiac transfer of adult stem cells can have a favorable impact on tissue perfusion and contractile performance of the infarcted heart. Several cell sources are being explored in an effort to regenerate infarcted myocardium, including hematopoietic stem cells, endothelial progenitor cells, cardiac resident stem cells, bone marrow–derived multipotent stem cells, and mesenchymal stem cells (MSCs). Each of these cell types may have its own profile of advantages, limitations, and practicability issues in specific settings. Studies comparing the regenerative capacity of distinct cell populations are scarce. Most clinical investigators have therefore chosen a pragmatic approach by using unselected bone marrow cells that contain different stem cell populations. Basic scientists, by contrast, are focusing more on specific cell populations in a quest to understand the biological foundations of cell therapy and to identify the most promising stem cells for cardiac regeneration.1 See p 214 MSCs are a rare population of self-renewing, multipotent cells present in adult bone marrow. Although MSCs represent <0.01% of all nucleated bone marrow cells, they can be readily expanded in vitro. In defined culture media, MSCs differentiate into several mesenchymal cell lineages, including cardiomyocytes.2,3 When injected into normal adult myocardium, MSCs differentiate into cardiomyocyte-like cells with sarcomeric organization.4 In an earlier study in pigs with myocardial infarction (MI), MSCs grafted into the infarcted area were shown to express muscle-specific markers and to improve regional wall motion.5 Ease of isolation, high expansion capability, and cardiomyogenic potential have led to the proposition that MSCs may be a good choice for cell-based therapies of MI.6 In a report published in this issue of Circulation , Dai et al7 have …

A variety of bioscaffolds have been developed as carriers for the delivery of mesenchymal stem cells (MSCs), however, many of them are unable to provide direct cell nourishment, a critical factor for survival and retention of MSCs at the site of delivery. Platelet lysate is a plasma-derived product rich in growth factors that can be turned into a gel matrix following the addition of calcium chloride. Our objective was to characterize growth factor and cytokine release of equine platelet lysate gel (ePL gel) encapsulated with MSCs over time and to measure the viability and proliferation of ePL gel-encapsulated MSCs for up to 14 days. The release of interleukin-1β (IL-1β), interleukin-10 (IL-10), transforming growth factor beta (TGF-β), vascular endothelial growth factor (VEGF), and platelet-derived growth factor BB (PDGF-BB), as well as fibrinogen degradation, were measured from ePL gel with and without equine bone marrow-derived MSCs and compared with MSCs in monolayer. MSC proliferation and viability within the gel were assessed up to 14 days. Compared with monolayer MSC cultures, significantly higher concentrations of IL-1β, IL-10, and TGF-β were measured from supernatants collected from ePL gel containing MSCs at various time points. Significantly lower concentrations of PDGF-BB were measured in the supernatant when MSCs were incorporated in ePL gel while VEGF tended to be increased compared with MSCs in monolayer. Incorporation in ePL gel for up to 14 days did not appear to affect viability and proliferation rates of MSCs as these were found to be similar to those measured in monolayer cell culture. ePL gel may have the potential to serve as bioscaffold for MSC delivery since it appears to support the proliferation and viability of MSCs for up to 14 days.

SummaryThe gap in knowledge of the molecular mechanisms underlying differentiation of human pluripotent stem cells (hPSCs) into the mesenchymal cell lineages hinders the application of hPSCs for cell-based therapy. In this study, we identified a critical role of muscle segment homeobox 2 (MSX2) in initiating and accelerating the molecular program that leads to mesenchymal stem/stromal cell (MSC) differentiation from hPSCs. Genetic deletion of MSX2 impairs hPSC differentiation into MSCs. When aided with a cocktail of soluble molecules, MSX2 ectopic expression induces hPSCs to form nearly homogeneous and fully functional MSCs. Mechanistically, MSX2 induces hPSCs to form neural crest cells, an intermediate cell stage preceding MSCs, and further differentiation by regulating TWIST1 and PRAME. Furthermore, we found that MSX2 is also required for hPSC differentiation into MSCs through mesendoderm and trophoblast. Our findings provide novel mechanistic insights into lineage specification of hPSCs to MSCs and effective strategies for applications of stem cells for regenerative medicine.

Osteoarthritis (OA), a chronic joint disease affecting over 500 million individuals globally, is characterized by the destruction of articular cartilage and joint inflammation. Conventional treatments are insufficient for repairing damaged joint tissue, necessitating novel therapeutic approaches. Mesenchymal stem cells (MSCs), with their potential for differentiation and self-renewal, hold great promise as a treatment for OA. However, challenges such as MSC viability and apoptosis in the ischemic joint environment hinder their therapeutic effectiveness. Hydrogels with biocompatibility and degradability offer a three-dimensional scaffold that support cell viability and differentiation, making them ideal for MSC delivery in OA treatment. This review discusses the pathological features of OA, the properties of MSCs, the challenges associated with MSC therapy, and methods for hydrogel preparation and functionalization. Furthermore, it highlights the advantages of hydrogel-based MSC delivery systems while providing insights into future research directions and the clinical potential of this approach.

Mesenchymal stem cell therapy for diabetes: An umbrella review.

The delivery of mesenchymal stem cells (MSC) in acute myocardial infarction (AMI) leads to significant preservation of myocardium and improved cardiac function. We have previously shown that the down-regulation of the tumor suppressor protein disabled-2 (Dab2) leads to increased MSC function in AMI. We sought to define the molecular mechanisms associated with down-regulation of disabled-2 and improved MSC function. We observed that the improvement in cardiac function following engraftment of Dab2-/- MSC was associated with modulation of the MSC secretome, in that of conditioned media conferred the same benefits as cell transplantation. To begin to define the down-stream targets of disabled-2 we completed a detailed Illumina array comparing Dab2 down-regulation by three methods (MSC treated with TGFß1 or MSC transfected with miR-145 or dab2:siRNA). Comparing gene expression in these three treatment groups to control MSC we identified 23 genes whose expression were similarly significantly modulated by dab2 down-regulation. Of this group we have focused to date on CAMKK1 as a possible regulator of the MSC secretome. CAMKK1, is a kinase with multiple down-stream targets including CAMK1, CAMKIV and Akt. Inhibition of CAMKK1 leads to an increase in pro-inflammatory cytokines and chemokines in the conditioned media of MSC. To determine if CAMKK1 over-expression was sufficient to induce an MSC like benefit in AMI we generated a plasmid vector in which CAMKK1 expression is regulated by the CMV promoter and the 5’-UTR RU5 enhancer element. We performed randomized blinded study in an AMI model in Sprague Dawley rats in which 500 ug of plasmid encoding CAMKK1 in 5 divided doses was injected into the infarct borderzone immediately after LAD ligation. CAMKK1 over-expression led to a significant improvement in cardiac function at 1, 2 and 8 weeks after AMI (Ejection Fraction at 8 weeks: CAMKK1: 83.2%±5.4% vs. Placebo: 51.7%±5.8%, p&lt;0.0001, baseline: 91.3%±4.3%). These data suggest that CAMKK1 is a key molecular regulator of the MSC secretome, and that the benefits associated with MSC therapy can be achieved through the direct over-expression of CAMKK1.

Purpose: Rotator cuff tear is a common injury that often requires surgical intervention due to poor healing capacity and high chances of retear. While surgical repair helps regain function, its long-term outcome is discrepant. Recently, mesenchymal stem cells (MSCs) have been explored as an adjunct therapy in rotator cuff repair. Studies suggest they may improve tendon integrity and reduce retear rates. To enhance MSC retention and viability at the repair site, carriers like fibrin glue have been explored. Fibrin glue provides a three-dimensional scaffold that mimics the final stage of clot formation and supports cell survival and proliferation. However, clinical studies on MSCs combined with commercial fibrin glue have reported contradictory results, with some showing clinical benefits and others indicating no significant improvement in clinical outcomes. This study was carried out to assess the viability of MSCs in commercial fibrin glue. Materials and Methods: MSC viability in commercial fibrin glue over a period of one-hour was compared to MSCs in suspension. Results: The results showed an immediate drop in cell viability within the fibrin glue group to 74.0% ± 2.00 at time 0, whereas the control group maintained a higher viability of 98.3% ± 0.58. This was followed by a gradual decline in both groups, with a comparable rate of decrease over time. Conclusion: These findings indicate that modifications in fibrin glue composition may be necessary to improve MSC survival and optimize regenerative outcomes in rotator cuff repair. Keywords: Mesenchymal stem cells; Fibrin glue; Viability assay; Rotator cuff tear

Event Abstract Back to Event Changes in T lymphocyte subsets accompany the clinical response to Mesenchymal Stem Cell (MSC) therapy – first experience in irradiation-induced colitis Jan Voswinkel1*, Jean-Jacques Lataillade2, Sabine Francois3, Mohammad Mohty1, Norbert C. Gorin1, Marc Benderitter3 and Alain Chapel3 1 Université Pierre et Marie Curie, Paris, Hôpital Saint Antoine, APHP, Haematology and Cell Therapy, France 2 Burn Treatment Center, Percy Military Hospital,, France 3 Radiological Protection and Human Health Division, Institute of Radiological Protection and Nuclear Safety, France Background: Therapy by Mesenchymal Stem Cells (MSC) facilitates functional recovery and dampens the systemic inflammatory response in radiation-induced colitis. Bone marrow-derived MSC from the patients´ children were injected to four patients. Patients and Methods: MSC were obtained by culture from bone marrow aspirates. A quantity of 2x106 - 6x106 MSC /kg were infused intravenously to the patients. Pain, hemorrhage, frequency of diarrheas and fistulisation as well as the lymphocyte subsets in peripheral blood were evaluated before MSC therapy and during the follow-up. Results: Two patients revealed a substantiated clinical response for pain and hemorrhage after MSC therapy. In one patient pain reappeared after 6 months and again substantially responded on a second MSC infusion. A beginning fistulisation process could be stopped in one patient resulting in a stable remission for more than 3 years of follow-up. The frequency of painful diarrhea diminished from an average of 6/d to 3/d after the first and 2/d after the 2nd MSC injection in one patient. A decline of CD4+ and CD8+ T lymphocytes and an increase of potentially regulatory CD25+ T cells accompanied the clinical response in this patient after the MSC injections. In all patients prostate cancer remained in stable complete remission. No toxicity occurred. Conclusion: A modulation of the lymphocyte subsets towards a regulatory pattern and diminution of activated T cells accompanies the clinical response in refractory irradiation-induced colitis. For patients with refractory chronic inflammatory and fistulising bowel diseases, systemic MSC injections represent a safe and effective option for salvage therapy. Keywords: lymphocyte immunology, Stem Cells, MSc, Colitis, Treg, cell therapy Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Translational immunology and immune intervention Citation: Voswinkel J, Lataillade J, Francois S, Mohty M, Gorin NC, Benderitter M and Chapel A (2013). Changes in T lymphocyte subsets accompany the clinical response to Mesenchymal Stem Cell (MSC) therapy – first experience in irradiation-induced colitis. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00039 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Mar 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Jan Voswinkel, Université Pierre et Marie Curie, Paris, Hôpital Saint Antoine, APHP, Haematology and Cell Therapy, Paris, France, jvoswinkel@aol.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jan Voswinkel Jean-Jacques Lataillade Sabine Francois Mohammad Mohty Norbert C Gorin Marc Benderitter Alain Chapel Google Jan Voswinkel Jean-Jacques Lataillade Sabine Francois Mohammad Mohty Norbert C Gorin Marc Benderitter Alain Chapel Google Scholar Jan Voswinkel Jean-Jacques Lataillade Sabine Francois Mohammad Mohty Norbert C Gorin Marc Benderitter Alain Chapel PubMed Jan Voswinkel Jean-Jacques Lataillade Sabine Francois Mohammad Mohty Norbert C Gorin Marc Benderitter Alain Chapel Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

BackgroundDiabetic foot ulcers (DFUs) represent a major complication of diabetes, often leading to poor healing outcomes with conventional treatments. Mesenchymal stem cell (MSC) therapies have emerged as a promising alternative, given their potential to modulate various pathways involved in wound healing. This study evaluates and compares the therapeutic potential of MSCs derived from perinatal tissues—human umbilical cord MSCs (hUCMSCs), human chorionic villi MSCs (hCVMSCs), and human decidua basalis MSCs (hDCMSCs)—in a diabetic wound healing model.MethodsWe performed in vitro and in vivo studies to compare the efficacy of hUCMSCs, hCVMSCs, and hDCMSCs. Mass spectrometry was used to analyze the secreted proteins of the MSCs. We incorporated the MSCs into a polyethylene glycol diacrylate (PEGDA) and sodium alginate (SA) hydrogel matrix with collagen I (Col-I) to evaluate their effects on wound healing.ResultsAll three types of MSCs promoted wound healing, with hUCMSCs and hCVMSCs showing stronger effects compared to hDCMSCs. Both hUCMSCs and hCVMSCs demonstrated robust wound healing kinetics, with enhanced keratinocyte proliferation (KRT14+/Ki67+ cells), maturation (KRT10/KRT14 ratio), and angiogenesis. In vitro studies demonstrated that the MSC-derived secretome enhanced keratinocyte proliferation and migration, endothelial cell function and stem cell recruitment, indicating robust paracrine effects. Mass spectrometry revealed a conserved set of proteins including THBS1 (thrombospondin 1), SERPINE1 (serpin family E member 1), ANXA1 (annexin A1), LOX (lysyl oxidase), and ITGB1 (integrin beta-1) which are involved in extracellular matrix (ECM) organization and wound healing, with the PI3K/AKT signaling pathway playing a central role. The PEGDA/SA/Col-I hydrogel demonstrated a unique balance of mechanical and biological properties and an optimal environment for MSC viability and function. Application of either hUCMSC- or hCVMSC-laden hydrogels resulted in accelerated wound closure, improved re-epithelialization, increased collagen deposition, and enhanced vascularization in vivo. ConclusionsMSCs From perinatal tissues particularly hUCMSCs and hCVMSCs significantly enhance diabetic wound healing through PI3K/AKT pathway activation while hDCMSCs exhibited weaker efficacy. The PEGDA/SA/Col-I hydrogel supports MSC viability and function offering a promising scaffold for DFU treatment. These findings underscore the potential of specific perinatal MSCs and optimized hydrogel formulations in advancing diabetic wound care.

Fresh human fibrin clots have been used clinically for more than 30 years to improve soft-tissue healing, albeit with scar tissue. Our results demonstrate that allogenic human MSCs, which reduce soft-tissue scarring, can be captured and remain active inside human fibrin clots, even in the absence a nutritive culture medium.

Mesenchymal stem cell (MSC) therapy is an emerging treatment strategy to counteract metabolic syndromes, including obesity and its comorbid disorders. However, its effectiveness is challenged by various factors in the obese environment that negatively impact MSC survival and function. The identification of these detrimental factors will provide opportunities to optimize MSC therapy for the treatment of obesity and its comorbidities. Dysregulated production of adipokines, a group of cytokines and hormones derived from adipose tissue, has been postulated to play a pivotal role in the development of obesity-associated complications. Intriguingly, adipokines have also been implicated in the modulation of viability, self-renewal, proliferation, and other properties of MSC. However, the involvement of adipokine imbalance in impaired MSC functionality has not been completely understood. On the other hand, treatment of obese individuals with MSC can restore the serum adipokine profile, suggesting the bidirectionality of the adipokine–MSC relationship. In this review, we aim to discuss the current knowledge on the central role of adipokines in the crosstalk between obesity and MSC dysfunction. We also summarize recent advances in the use of MSC for the treatment of obesity-associated diseases to support the hypothesis that adipokines modulate the benefits of MSC therapy in obese patients.

Currently, equine metabolic syndrome (EMS), an endocrine disease linked to insulin resistance, affects an increasing number of horses. However, little is known about the effect of EMS on mesenchymal stem cells that reside in adipose tissue (ASC). Thus it is crucial to evaluate the viability and growth kinetics of these cells, particularly in terms of their application in regenerative medicine. In this study, we investigated the proliferative capacity, morphological features, and accumulation of oxidative stress factors in mesenchymal stem cells isolated from healthy animals (ASCN) and horses suffering from EMS (ASCEMS). ASCEMS displayed senescent phenotype associated with β-galactosidase accumulation, enlarged cell bodies and nuclei, increased apoptosis, and reduced heterochromatin architecture. Moreover, we observed increased amounts of nitric oxide (NO) and reactive oxygen species (ROS) in these cells, accompanied by reduced superoxide dismutase (SOD) activity. We also found in ASCEMS an elevated number of impaired mitochondria, characterized by membrane raptures, disarrayed cristae, and vacuole formation. Our results suggest that the toxic compounds, accumulating in the mitochondria under oxidative stress, lead to alternations in their morphology and may be partially responsible for the senescent phenotype and decreased proliferation potential of ASCEMS.